1. Field of the Invention
The present invention relates to an electronic appliance, and a method for combining together laser light, that can reduce speckles.
2. Description of Related Art
It is known that, when a coarse surface, such as the surface of paper or a wall, is illuminated with coherent light, such as laser light, and the light transmitted or reflected is inspected, bright and dim spots are observed. These bright and dim spots are generally called speckles. Speckles degrade the image projected from laser projectors, and various methods for reducing speckles have conventionally been proposed.
For example, according to Japanese Patent Application Publication No. 2012-73476, polarized light emitted from a laser light source enter a polarizing beam splitter (PBS) so that a p-polarized light component is transmitted while an s-polarized light component is reflected. The two components then travel different optical paths before they are eventually combined together. In this way, two patterns of speckles that have traveled different optical paths (optical path lengths) are overlaid together, and thereby the contrast of speckles is reduced.
In a configuration like the one described just above where a PBS is used to split and combine light, a deviation in the angle at which light is incident greatly affects the angle at which the light is reflected. This makes it difficult to combine light accurately, leading to a diminished effect of reducing speckles.
Against the background discussed above, an object of the present invention is to provide an electronic appliance, and a method for combining together laser light, that can combine split light accurately to reduce speckles.